1. Field
The present embodiments relate to an organic light-emitting device including an anode, a cathode having a double-layered structure, and an emission layer between the anode and the cathode.
2. Description of the Related Technology
With the advent of the 21st century, the trend toward an information-oriented society has been accelerating, and along with a necessity for receiving and transmitting information anytime anywhere, conventional cathode-ray tube (CRT) displays are being replaced with flat panel displays. One of the most common types of flat panel displays currently being used are liquid crystal displays (LCDs). This is because LCDs are lightweight and have low power consumption. However, since an LCD is a passive light-emitting device and not a self-light emitting device, the LCD has technical limitations in terms of a contrast ratio, a viewing angle, and area size. Accordingly, new flat panel displays that can overcome such technical limitations are being developed worldwide. One type of such new flat panel display uses organic light emitting diodes (OLEDs). OLEDs can be driven at low power, have a wide viewing angle and quick response speed, and are self-light emitting, light weight, and thin. Accordingly, research and development have been accelerated in Japan, Korea, and the US regarding practical uses of OLEDs.
A cathode of an active matrix organic light emitting device (AMOLED) currently used in mobile displays is formed by deposition of a combination of magnesium (Mg) and silver (Ag). However, the cathode may have an area specific resistance (ASR) as high as ˜50 Ω/sq. at a thickness of 120 Å, and thus be not applicable in 4-inch or larger mobile devices due to an IR drop problem.